diff options
Diffstat (limited to 'kernel/futex.c')
-rw-r--r-- | kernel/futex.c | 114 |
1 files changed, 26 insertions, 88 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 05e88562de68..83404124b77b 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -32,30 +32,13 @@ * "But they come in a choice of three flavours!" */ #include <linux/compat.h> -#include <linux/slab.h> -#include <linux/poll.h> -#include <linux/fs.h> -#include <linux/file.h> #include <linux/jhash.h> -#include <linux/init.h> -#include <linux/futex.h> -#include <linux/mount.h> #include <linux/pagemap.h> #include <linux/syscalls.h> -#include <linux/signal.h> -#include <linux/export.h> -#include <linux/magic.h> -#include <linux/pid.h> -#include <linux/nsproxy.h> -#include <linux/ptrace.h> -#include <linux/sched/rt.h> -#include <linux/sched/wake_q.h> -#include <linux/sched/mm.h> #include <linux/hugetlb.h> #include <linux/freezer.h> #include <linux/memblock.h> #include <linux/fault-inject.h> -#include <linux/refcount.h> #include <asm/futex.h> @@ -476,7 +459,7 @@ static u64 get_inode_sequence_number(struct inode *inode) /** * get_futex_key() - Get parameters which are the keys for a futex * @uaddr: virtual address of the futex - * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED + * @fshared: false for a PROCESS_PRIVATE futex, true for PROCESS_SHARED * @key: address where result is stored. * @rw: mapping needs to be read/write (values: FUTEX_READ, * FUTEX_WRITE) @@ -500,8 +483,8 @@ static u64 get_inode_sequence_number(struct inode *inode) * * lock_page() might sleep, the caller should not hold a spinlock. */ -static int -get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_access rw) +static int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key, + enum futex_access rw) { unsigned long address = (unsigned long)uaddr; struct mm_struct *mm = current->mm; @@ -538,7 +521,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_a again: /* Ignore any VERIFY_READ mapping (futex common case) */ - if (unlikely(should_fail_futex(fshared))) + if (unlikely(should_fail_futex(true))) return -EFAULT; err = get_user_pages_fast(address, 1, FOLL_WRITE, &page); @@ -626,7 +609,7 @@ again: * A RO anonymous page will never change and thus doesn't make * sense for futex operations. */ - if (unlikely(should_fail_futex(fshared)) || ro) { + if (unlikely(should_fail_futex(true)) || ro) { err = -EFAULT; goto out; } @@ -677,10 +660,6 @@ out: return err; } -static inline void put_futex_key(union futex_key *key) -{ -} - /** * fault_in_user_writeable() - Fault in user address and verify RW access * @uaddr: pointer to faulting user space address @@ -1611,13 +1590,13 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_READ); if (unlikely(ret != 0)) - goto out; + return ret; hb = hash_futex(&key); /* Make sure we really have tasks to wakeup */ if (!hb_waiters_pending(hb)) - goto out_put_key; + return ret; spin_lock(&hb->lock); @@ -1640,9 +1619,6 @@ futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) spin_unlock(&hb->lock); wake_up_q(&wake_q); -out_put_key: - put_futex_key(&key); -out: return ret; } @@ -1709,10 +1685,10 @@ futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2, retry: ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ); if (unlikely(ret != 0)) - goto out; + return ret; ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE); if (unlikely(ret != 0)) - goto out_put_key1; + return ret; hb1 = hash_futex(&key1); hb2 = hash_futex(&key2); @@ -1730,13 +1706,13 @@ retry_private: * an MMU, but we might get them from range checking */ ret = op_ret; - goto out_put_keys; + return ret; } if (op_ret == -EFAULT) { ret = fault_in_user_writeable(uaddr2); if (ret) - goto out_put_keys; + return ret; } if (!(flags & FLAGS_SHARED)) { @@ -1744,8 +1720,6 @@ retry_private: goto retry_private; } - put_futex_key(&key2); - put_futex_key(&key1); cond_resched(); goto retry; } @@ -1781,11 +1755,6 @@ retry_private: out_unlock: double_unlock_hb(hb1, hb2); wake_up_q(&wake_q); -out_put_keys: - put_futex_key(&key2); -out_put_key1: - put_futex_key(&key1); -out: return ret; } @@ -1992,20 +1961,18 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, retry: ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ); if (unlikely(ret != 0)) - goto out; + return ret; ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, requeue_pi ? FUTEX_WRITE : FUTEX_READ); if (unlikely(ret != 0)) - goto out_put_key1; + return ret; /* * The check above which compares uaddrs is not sufficient for * shared futexes. We need to compare the keys: */ - if (requeue_pi && match_futex(&key1, &key2)) { - ret = -EINVAL; - goto out_put_keys; - } + if (requeue_pi && match_futex(&key1, &key2)) + return -EINVAL; hb1 = hash_futex(&key1); hb2 = hash_futex(&key2); @@ -2025,13 +1992,11 @@ retry_private: ret = get_user(curval, uaddr1); if (ret) - goto out_put_keys; + return ret; if (!(flags & FLAGS_SHARED)) goto retry_private; - put_futex_key(&key2); - put_futex_key(&key1); goto retry; } if (curval != *cmpval) { @@ -2090,12 +2055,10 @@ retry_private: case -EFAULT: double_unlock_hb(hb1, hb2); hb_waiters_dec(hb2); - put_futex_key(&key2); - put_futex_key(&key1); ret = fault_in_user_writeable(uaddr2); if (!ret) goto retry; - goto out; + return ret; case -EBUSY: case -EAGAIN: /* @@ -2106,8 +2069,6 @@ retry_private: */ double_unlock_hb(hb1, hb2); hb_waiters_dec(hb2); - put_futex_key(&key2); - put_futex_key(&key1); /* * Handle the case where the owner is in the middle of * exiting. Wait for the exit to complete otherwise @@ -2216,12 +2177,6 @@ out_unlock: double_unlock_hb(hb1, hb2); wake_up_q(&wake_q); hb_waiters_dec(hb2); - -out_put_keys: - put_futex_key(&key2); -out_put_key1: - put_futex_key(&key1); -out: return ret ? ret : task_count; } @@ -2567,7 +2522,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked) */ if (q->pi_state->owner != current) ret = fixup_pi_state_owner(uaddr, q, current); - goto out; + return ret ? ret : locked; } /* @@ -2580,7 +2535,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked) */ if (q->pi_state->owner == current) { ret = fixup_pi_state_owner(uaddr, q, NULL); - goto out; + return ret; } /* @@ -2594,8 +2549,7 @@ static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked) q->pi_state->owner); } -out: - return ret ? ret : locked; + return ret; } /** @@ -2692,12 +2646,11 @@ retry_private: ret = get_user(uval, uaddr); if (ret) - goto out; + return ret; if (!(flags & FLAGS_SHARED)) goto retry_private; - put_futex_key(&q->key); goto retry; } @@ -2706,9 +2659,6 @@ retry_private: ret = -EWOULDBLOCK; } -out: - if (ret) - put_futex_key(&q->key); return ret; } @@ -2853,7 +2803,6 @@ retry_private: * - EAGAIN: The user space value changed. */ queue_unlock(hb); - put_futex_key(&q.key); /* * Handle the case where the owner is in the middle of * exiting. Wait for the exit to complete otherwise @@ -2961,13 +2910,11 @@ no_block: put_pi_state(pi_state); } - goto out_put_key; + goto out; out_unlock_put_key: queue_unlock(hb); -out_put_key: - put_futex_key(&q.key); out: if (to) { hrtimer_cancel(&to->timer); @@ -2980,12 +2927,11 @@ uaddr_faulted: ret = fault_in_user_writeable(uaddr); if (ret) - goto out_put_key; + goto out; if (!(flags & FLAGS_SHARED)) goto retry_private; - put_futex_key(&q.key); goto retry; } @@ -3114,16 +3060,13 @@ retry: out_unlock: spin_unlock(&hb->lock); out_putkey: - put_futex_key(&key); return ret; pi_retry: - put_futex_key(&key); cond_resched(); goto retry; pi_faulted: - put_futex_key(&key); ret = fault_in_user_writeable(uaddr); if (!ret) @@ -3265,7 +3208,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, */ ret = futex_wait_setup(uaddr, val, flags, &q, &hb); if (ret) - goto out_key2; + goto out; /* * The check above which compares uaddrs is not sufficient for @@ -3274,7 +3217,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, if (match_futex(&q.key, &key2)) { queue_unlock(hb); ret = -EINVAL; - goto out_put_keys; + goto out; } /* Queue the futex_q, drop the hb lock, wait for wakeup. */ @@ -3284,7 +3227,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); spin_unlock(&hb->lock); if (ret) - goto out_put_keys; + goto out; /* * In order for us to be here, we know our q.key == key2, and since @@ -3374,11 +3317,6 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, ret = -EWOULDBLOCK; } -out_put_keys: - put_futex_key(&q.key); -out_key2: - put_futex_key(&key2); - out: if (to) { hrtimer_cancel(&to->timer); |